Method of preparation of aliphatic arsenical derivatives from acetoarsenious anhydride



Patented Dec. 30, 1924.

UNITED STATES CARL OECHSLIN, OF ABLON, FRANCE.

METHOD OF PREPARATION OF ALIPHATIC ARSENICAL DERIVATIVES FROM ACETO-ARSENIOUS 'ANHYDR-IDE.

No Drawing.

To all whom it may concern:

Be it known that I, CARL OEoiIsLIN, a citizen of the SwissConfederation, and resident of Ablon, in the Republic of France, haveinvented a new and useful Method of Preparation of Aliphatic ArsenicalDerivatives from Aceto-Arsenious Anhydride, of which the following is aspecification.

A. Pictet and Bon have isolated the aceto-arsenious anhydride, As(O COH(B1111. 33, p. 11394905.)

It has been ascertained that when heated at ordinary pressure, thisproduct will be decomposed in a regular and substantially quantitativemanner, with escape of carbon dioxide and distillation of acetic acid;there will remain a solid residue wherein the arsenic is combined withthe carbon; (ASCH)X. This reaction therefore constitutes a new method ofintroducing arsenic into an aliphatic body.

By oxidizing this product (AsCH) there is obtained an arse-nical acidwhich is but slightly soluble in water and alcohol and forming sodiumsalts which are very soluble in water and are precipitated by alcohol.

EwampZe.-1OO grams of arsenious acid are dissolved on the water bath ingrams of acetic anhydride by stirring. The addition of a very smallquantity of sodium acetate may accelerate the solution to a very markeddegree. When completely dissolved, the temperature is gradually raisedto C. and until the cessation 01 the escape of carbon dioxide and of thedistillation of acetic acid. By producing a vacuum at the end of theoperation, the mass will swell up, and becomes solid and friable.

Application filed September 14, 1922. Serial No. 588,183.

The substance is very finely powdered and extracted several times bycaustic soda or dilute hydrochloric acid, and at the end of theoperation this will afford a gray powder which is insoluble in mostsolvents and has the formula (AsCI-D The said product is placed insuspension in a sodium carbonate solution, and the same is coo-led andoxidized by hydrogen peroxide in slight excess; the whole of thesubstance becomes dissolved. When filtered through lampblack, thesolution is colourless, and acidulation with hydrochloric acid willafford a precipitate of a white powder which is but slightly soluble inwater and alcohol but is very soluble in the alkalis.

The formula for this body is (HCzAs- Having now particularly describedand ascertained the nature of my sald invention and in what manner thesame is to be perture, and subsequently subjecting the prod- M uct thusobtained, and havin the formula o (As: CH) to the action of hydrogenperoxide.

In witness whereof I have hereunto signed my name.

CARL OECHSLIN.

